将一列从数据库表复制到另一数据库表sql server中的另一列

Question

I had two databases (A and B), both were identical until I messed up one column in Table T1 on database A... basically set all records in that column to NULL. How do I update that incorrect column in T1 on database A with the correct data from its equivalent column from database B?

My insert command did not work as there are more columns in T1 on database A which do not allow null values to be inserted.

insert into A.dbo.finance (finishdate)
select finishdate 
from B.dbo.finance

I tired to do an inner join, but it says "multi-part identifier could not be bound". Unfortunately the data in the other tables in database A has since changed hence simply using database B is not an option :-)

Could someone please assist?

Answer 1

If ID is the id column of both tables, you should join them and update the one you want:

UPDATE A.dbo.finance
SET    finishdate = B.finishdate 
FROM   A.dbo.finance A
       JOIN B.dbo.finance B
           ON A.ID = B.ID

Answer 2

DATABASE B

Select finishdate into ##temp from dbo.finance B where 1 = 1

DataBase A

    insert into dbo.finance(finishdate)
    select * from ##temp t where NOT EXISTS
(Select 1 from dbo.finance WHERE finishdate <> t.finishdate  )